A179655 Digital root of n-th abundant number.

3, 9, 2, 6, 3, 9, 4, 6, 3, 9, 2, 6, 3, 7, 9, 6, 8, 3, 7, 9, 6, 1, 3, 5, 9, 4, 6, 3, 9, 6, 3, 5, 9, 6, 3, 7, 9, 6, 3, 5, 9, 6, 3, 7, 9, 2, 6, 1, 3, 9, 4, 6, 8, 3, 9, 6, 3, 9, 6, 8, 3, 9, 2, 6, 1, 3, 9, 6, 3, 7, 9, 2, 6, 3, 5, 9, 6, 3, 7, 9, 6, 8, 1, 3, 9, 4, 6, 8, 3, 9, 2, 6, 3, 5, 9, 4, 6, 3, 9, 2, 6, 3, 9, 6, 8

Offset: 1

Author

Jason G. Wurtzel, Jul 22 2010

Keywords

• nonn
• base

Examples

			The 11th abundant number is 56. 5+6=11. 1+1=2. The digital root is 2.
		

Crossrefs

Cf. A005101.

Programs

Mathematica

abQ[n_] := DivisorSigma[1, n] > 2 n; Mod[ Select[ Range@ 500, abQ], 9] /. 0 -> 9 (* Robert G. Wilson v, Aug 23 2010 *)

Extensions

More terms from Robert G. Wilson v, Aug 23 2010